Why do you keep a personal knowledge base? What are you trying to accomplish by saving content? What insights do you want to discover? What tasks do you want to achieve?
Although high general intelligence is common among hackers, it is not the sine qua non one might expect. Another trait is probably even more important: the ability to mentally absorb, retain, and reference large amounts of ‘meaningless’ detail, trusting to later experience to give it context and meaning. A person of merely average analytical intelligence who has this trait can become an effective hacker, but a creative genius who lacks it will swiftly find himself outdistanced by people who routinely upload the contents of thick reference manuals into their brains.
I'm a researcher. Absorbing data in a "blue sky" kind of way ("no idea if i'll need this, this doesn't serve any explicit purpose, but hey it seems interesting") is a survival trait.
This. I take notes of concepts that I don’t clearly understand/agree but have a gut feeling that is interesting, and as I read it repeteadly overtime I often get surprised by how the concept evolves on my mind.
Being able to let go of data is similarly just as important, being able to have control over an internally oriented structure that allows for this process of accepting, selecting, absorbing, checking, retaining, and rejecting information, this is important for survival period.
Our ideas of memory come from our previous ideas of memory. It's much more malleable than you may have grown to understand.
It really is like bread crumbs when you have deal with things like information overload. There's that whole idea of a 'memory palace' that I like to think about before I go to sleep, because it gives me a structure to meditate on at the end of the day, the thoughts I want to retain and arrange in the ways I'm curious about retaining and arranging them.
A lot of the information we collect can appear ordered, but unless it's a rigorous order proven mathematically, there's no real way to prove anything about the efficiency of our memory. Some thoughts may be useful tomorrow and others may be useful 10 years from now.
So I think it's fun to give it a structure I remember and can travel into, because I chose how to organize it over a very long period of time.
But ultimately I think it depends on ways you are most comfortable thinking about information. My imagination tends to be very visual.
- Recording and crystallizing ideas: most deep thoughts and informed opinions about things often don't materialize on first try. They are the result of many iterations, pivots and revisions. Writing them down helps one regain context quickly after leaving them for a while, which allows one to make incremental progress without being susceptible to the fallibility of memory searches. Writing is also frequently the best way to teach oneself something and to push oneself to identify gaps in knowledge and thinking.
- Sleep aid: committing ideas to (virtual) paper helps unburden them from one's active memory. This has inadvertent therapeutic effects as well. I'm one of those people who has tons of ideas racing in my head all the time, so this helps me sleep at night. On a related note, Cognitive Behavioral Therapy or CBT (for managing emotions) can also be done through written therapy.
- Business ideas/hobby ideas: list of stuff to do when the right combination of opportunities arises. You can have ideas but not all ideas are ripe for execution. Having them in a cache as one is constantly monitoring the environment helps one time their deployment better.
- Latent solutions to problems: Richard Feynman had a trick where he'd be constantly thinking about 6 problems at any given time. When an attack presented itself due to sheer chance, he was able to execute on it quickly, and make himself look like a genius when in fact he had been thinking about about the problem for a long time and was merely lying in wait for the right piece of the puzzle to come along.
- Jokes/good turns of phrases: not for the purpose of plagiarism, but sometimes one needs a bon mot or an apt phrase for a presentation or piece of writing. Having a store of such phrases to synthesize from is much more reliable than drawing from memory alone. Many good writers/presenters aren't Mozart-like geniuses who can produce polished work on-demand: many maintain disciplines like this to aid in producing quality work even when their memory fails them.
- Travel destinations: sometimes we read about an interesting place and tell ourselves "we'll visit some day" but then never do because when the next long weekend comes up, we'd have forgotten all about it. Keeping a list helps one to quickly converge on a destination when a vacation opportunity arises.
Yes I do. I keep everything in a single Google Docs document and re-read it from time to time. Maybe it's just me, but I always find it a rewarding experience. (ymmv)
I’ve realized recently that I spend hours and hours a week reading and saving stuff to Evernote. Like I’m always in research mode. I think focused research is good for the career, but unfocused is just a distraction and waste of time. I save sooo much stuff and rarely go back to read it.
My one idea for recovering the lost/wasted time reading and saving this information is curating and publishing it online as blog posts for others to learn from. I’ve spent so much time categorizing an filtering through information out there, only to have it sitting in a private file, might as well make it public for humanity’s benefit (and my own).
This is exactly my experience too. I almost never go back to my notes. Only value creating notes is actual act of creating notes, it doesn't really matter what you use for it.
This is exactly the problem that I seem to have. I'm looking for a way to turn that unfocused research into something productive, and it's a tough problem to solve.
Me too, especially with books. I kept getting the feeling it was a waste to read all this great stuff and not use it. Even when I took notes, I never went back to them.
So I started doing this:
- Create 1 file per book (I keep it all in Google Drive)
- The problem is my notes are huge, so at the top of the file I include a TL;DR
- Include in the TL;DR a list of actions: things I can put to use straight away. I copy stuff onto a personal Trello too, so I don't forget
- Also when I'm working on something relevant I can go back to the TL;DR (instead of searching through all the notes)
On top of this, I try to read books that are relevant to what I'm currently working on. I have a huge backlog of books I'd like to read on all sorts of things, but I'll hold back if I think it'll make more sense to read them later on.
My reason for keeping a knowledge base is to forget less of what I learn every day.
I used to use Evernote for this but it wasn't quite working because of constant context switching and lack of spaced repetition.
So I wrote open source program called Dnote [0] and have been use it every day for the last year to store my learning. To minimize distraction, it works as browser extensions, cli, and IDE plugin. And I automated the spaced repetition by writing a cron job to send me digests every Friday.
I'm really into taking notes -- both written and typed. The tactile part of taking notes helps me register things better and the notes themselves greatly help with recall. For written notes, I use Peter Pauper notebooks (https://www.peterpauper.com/) and Staedtler pens (https://www.staedtler.com/intl/en/products/products-for-colo...). I'm a sucker for good stationery. For typed notes, I use Google Keep on my phone and the Notes app on my Mac.
Lately I've been using screen recording to create video notes. I developed an app called Outclip (https://checkoutclip.com) with my buddy. Although the app is meant for a different purpose (bug reporting) I use it to screen record as I'm doing things (like configuring an AWS service for instance) in case I have to repeat the steps later.
Refreshing the context when I resume some project.
I get my mind back in the groove from sometimes years ago by just opening my orgmode section or file.
The brain finds the connections again and the thought train picks up and off I go.
As a side note, I use orgmode and I wouldn't consider any other program (that I know of) for a specific reason -
What other setup could I be GUARANTEED of being able to pickup in 5, 10 ,30 years and have it work just as it did?
A paper notebook for sure but orgmode gives me much more (and less in some areas).
orgmode and emacs lets me INVEST my time and effort and know I won't lose the data and time because some webservice thing went down/changed business models/lost interest.
You bring up a good point about longevity. I currently use OneNote which was easy to be effective immediately taking notes with rich content, but I know there's always the risk of it shutting down forcing me to deal with the process of recovering my notes onto a different platform.
The key question when reading any article/book/whatever is the following: "if anything, what is actually important enough to remember from this article?", or in the case of PKBs: "What should be in my PKB and what should be discarded?"
By asking yourself this question explicitly and then actually writing down the key points you practice your own judgment on what is worth remembering and what is not.
Now the added benefit of a PKB is that you can actually keep these key points in a central location and reference them in other contexts or share them with others. You are basically doing prework for later (research) questions you might have. However I would say the biggest benefit is the process; explicitly writing down what is important and discarding what is not.
For more on this subject I recommend following @fortelabs on Twitter. He does a lot of interesting writing on the subject.
If anyone is interested, the term for this field is "personal knowledge management."
There are a few basic principles that can help keep the system organized and useful.
Personally I use Google Keep and OneNote: every weekend I funnel the unstructured thoughts, ideas and realizations into a structured format organized in OneNote. It takes a bit of time, but I can look back on any of my notes on programming or real estate or marketing or psychology and instantly find them useful.
Please, for the love of all that is open source, someone create an open alternative to OneNote. It’s easily one of the best Microsoft tools ever, and there doesn’t seem to be a good equivalent. It also seems like the perfect pinboard-style lifestyle business.
For early adopters it would be enough to have a great import functionality. There are lots of mobile note taking apps that support cloud saves or exports/saves in open formats, so people could use one of them and save to a folder on Dropbox or Gdrive and have the main app source content from there.
I used to keep a tonne of stuff in Evernote, but have since moved to Standard Notes[1]. I generally have everything super organized, but allow the overall collection of knowledge to look messy. A bit like our brains, knowledge dumps can appear messy, but are actually organized.
Emacs noob here. I came to Emacs through learning http://overtone.github.io/ and see a lot of personal knowledge management tools that use Emacs (Org mode). Can anyone recommend some engaging Emacs tutorials to help me find my bearings?
I journal to keep a health record. I know someone who had cancer and was able to prove with photos that their chemo wasn't working, the cancer was getting worse, and get their chemo changed sooner rather than later. A personal health database can be a powerful tool for health management. I also keep articles pertinent to my health, plus links to interesting HN comments, etc.
When trying to decide where to move next, I kept a lot of information on various places that were under consideration. This included not only US states and cities, but at least one other country as well.
I did a lot of therapy in my youth. I find that having stuff I wrote that I can refer back to is enormously helpful for my state of mind, for keeping my goals on track, for tracking progress, etc.
I see the world differently from most people. If I don't keep track of links to articles, comments and research, I get dismissed a lot as crazy, not knowing what the hell I am talking about, etc. and other people typically do not back me up, even if I am saying it in the same forum where I originally read the information.
So I try to keep track of certain kinds of info so that the next time I make a comment on that subject, I can back it up without having to put up with so much disrespectful crap off of people. They don't have to agree with me or see the world the way I do, but I don't care to wallow in their contempt either. Supporting links goes a long way towards preventing the worst of such behavior.
(There are probably other reasons. This answer not guaranteed to be comprehensive.)
As a side note, there is an online course called "Building a Second Brain" that shows how to create an effective personal knowledge base: https://www.buildingasecondbrain.com/
It's kinda pricey, and I'm taking the course right now. But I find it's pretty effective overall. It uses evernote as the default platform for your PKM.
Previously I would save notes and never use them. Now my notes are set up in a way that I get more projects done. Having reference material progressively summarized makes collecting ideas and shaping it into a deliverable way easier. Loading context for a project is way easier with a system like this, it makes an interruption much less painful.
The other benefit of taking the course is the forum, plenty of smart people to meet, discuss pkm and other ideas.
He's coming out with a book so you might want to wait on it. A proper notetaking system is important to me, so it was worth it for me, but I'd wait on the book because he tends to ramble on the podcast.
It's basically an organization system that serves as an adjunct to "getting things done". GTD's system relies on "filing non-actionable items", but it doesn't really explain how to do that. Traditionally, people would rely on filing cabinets or whatever. BASB relies on evernote to keep basically anything information in there that can quickly be retrieved (becuase you're going to forget years later). And when you later need to the information, you can criss-cross the data for more creative output.
Just saw this intro to Emacs org mode. Thanks! I asked for some recommendations on getting started in a different section of thread. I appreciate the tip!
About fifteen years ago I started to use a wiki as my personal knowledge base. Since then I've added several thousands pages. Last year I started using Evernote, primarily because it works on the phone syncs with my desktop, and since then I don't use the wiki much. The good thing about Evernote is that you can export the notes to xml, so if they ever stop, I still have access to my notes.
I started to use the wiki as a notebook for problems that were too complicated to solve in one day. Plus it was a good way to keep these notes together, searchable, from home and work. I started to use it for installation and configuration manuals for applications that I had to maintain. I did keep work related stuff in it, but only general things like how to setup a webserver.
My notes are the base of my day to day. I use simple txt files synced with my phone, can't stand the lag of opening OneNote and Evernote and the bugs that always deleted my items on Wunderlist. I curate everything weekly at least, try to keep the content easy to read in 10 minutes or so for the main file (tactics and strategies is the name of this file, but I put a lot information on it, more about below). I have a lot of these txt, the main ones being tasks, tactics and strategy, accounting and a lot others for personal projects, hobbies and other subjects.
The task file is the one always opened, there are my pressing issues and there I'll note anything that later I'll pass to the other files. The most important though is the tactics/strategy one, where I write details, thoughts of my life, business strategies and general stuff that I like to read at least every week, the projects I want to do next, hobbies I want to try, advice that I like to read, and even if I have some of this etched on my mind sometimes it's a great north on a confusing day. It's great to read about this idea I had a week ago and now completely forgot about because I was focused at the current issue. Writing is also great to organize the thoughts, I had so many breakthroughs just by reading and writing on these files. It's an extension of my memory and my process.
How do you go back to your tactics/strategy notes? For me, I never stumble across old ideas when they would actually be relevant, but systemic review of these ideas seems like a big hassle.
This is where you would add in other techniques to aid you.
I don't know how well it works but the zettelkasten method is a way to organise your notes contextually, with only a little manual overhead. You can also add in what they call "structural notes" (i.e. tables of content) to let you quickly find your way. This would aid you in building up a mental map if you will of what notes you have, and to let you quickly find whatever you can't remember.
Then you can do things like SRS flashcards to continually refresh your memory about topics. They're originally meant for just learning things in the first place but they could easily be adapted to keep throwing back your ideas at you at irregular intervals. That keeps the ideas floating around in your mind without you having to manually go and read them.
I read this specific file weekly (or when lost) and as I read it I’ll often erase stuff that aren’t too useful anymore (or move to other file). It’s important to keep this file in a size small enough for me to enjoy reading it often, and so I force myself to only keep the winners there.
I read the other 20 or so files monthly or when looking for something specific.
I have three modes when it comes to my career and skill development.
- learning what I need to know about my specific job (institutional knowledge). Even if my title is “Senior Developer”, in reality I usually have a fair amount of architectural level responsibilities and meetings with C level of people working at small companies. For that, I ask a lot of questions and take notes with Evernote or if I take notes on paper, I take a picture. Evernote is surprisingly good translating my writing to text for searching.
I keep a personal knowledge base so I can prepare for a meeting and be ready to answer questions.
- If I am introducing a new to the company technology, process or framework, I have a list of links that fellow developers or my manager (who is technical) to review.
- getting “interview ready”. About three months before I start seriously looking for a job,I freshen up on architectural subjects and make sure I can talk the talk. I keep a list of bookmarks and PDFs. Again, I am at a point in my career where no one asks me to do a whiteboard coding session but they do want to talk architecture. As an in the weeds developer, I know sound architecture but I don’t talk about it every day.
- I have a list of topic areas that I need to study to feel in the gaps to really consider myself a “full stack developer/architect”. But I’m usually only focused on one thing at the time. But if I find an interesting “getting started” walk through about another topic that’s on my radar, I bookmark under a folder “Things to Learn”. Right now, that’s getting deeper into AWS, Docker, NodeJS, and React.
I keep a record of any info that I learn (organized by topic) in Workflowy. I even keep a note of everything I do.
Basically my goal is to decrease the chance of going through the same process of learning something, multiple times.
I also think of it as a cache for Google. I sometimes search my knowledge base before searching Google.
For example: how to delete duplicate lines in emacs? I just found it in my knowledge base in under 3 seconds but would have taken more time googling (also more distracting)
You hit the nail on the head. I run a personal instance of Dokuwiki, and find that this is my L1 cache for knowledge. Vim, Git, Linux... all the stuff I use the most often is there and organized in the way I find optimal.
It's also very convenient to have a reference on various devices that you own. Specs, links to manuals, common troubleshooting steps and an inbox of future work and enhancements.
I don't know about others but I actually don't. I found that I am wired to remember search terms exactly as is (not saying photographically) or at least sequences of searches and I let Google do the rest. I have been able to go back to topics I had researched years ago and almost retrace my search and find what I found earlier after many years. Must be why I am a "breadth" kind of person.
Same. Especially with ideas I have a mental map. For instance I find myself revisiting the topic of type systems every 3-4 years (don't me ask me why - I just am a sucker that way) and each time I find it a lot easier to revisit my last mental breadcrumbs rather falling back on books or notes I may have taken. I think laziness has honed me this way.
Interesting that the question is why and not how. I do it because the same material (say calculus) can be presented in many different ways, but my brain learned the material by following the steps in logic that I used the first time.
I've found with several groups of material that reconnecting your brain's old steps in logic is way easier. The same material in a different way can feel interestingly very foreign.
At work I maintain a running txt file that acts as a journal, a time tracker to help with timesheets, and a scratchpad for real-time notes (meeting notes, action items, email drafts, code/config). I start a new txt file each year. Each week starts with a header with some goals for the week. Each day follows a similar pattern of highlighting priorities for the day.
Since it's txt file it opens quickly, is easily scannable and searchable. I will sometimes tag entries with phrases that I know I'm more likely to use later when I'm looking for something. The txt file is stored in dropbox and is typically open all day on whatever device I happen to be on.
I've found that tools that organize by things by folder or tag (Notational Velocity, Evernote) don't work for me - I lose track of where something went. Organizing by calendar/time allows me to remember "oh, the thing I'm looking for occurred before this thing".
I don't really have a KB, I store information in gmail, google docs, bookmarks, code repos, and txt files. I keep that information because it's useful for work and personal info I keep needing to come back to or could be useful in the future.
I have been saving most of mine as browser bookmarks, if I see something interesting or a solution on stack overflow I bookmark it. Then I export those bookmarks occasionally for safe keeping.
I usually just re-search google for a solution or item I'm looking for. But sometimes I search my bookmarks just to find exactly what I used before.
I also have a few snippets text file where I add interesting code related snippets. And some google docs files that are super easy to search too. Gmail is also a great tool, with boomerang so I can have something fly back in my inbox someday or a certain time of year.
All in all I rarely have a hard time finding anything I'm looking for by using google, bookmarks, code repos and snippets.
I have a long term personal project that was well outside my capabilities when I first took it up. I've been using the same knowledge base app (Devon) that I used for my thesis and book. I find that it's much easier to recover stuff that I've "found out about" but didn't "learn".
Diabetis runs in my family. So i tend to keep a diary where i track the Fasting and Post Prandial blood sugars of my parents. Over time (almost 8 years) it has given me an understanding to seasonal influences on diabetis and also how they are responding to a particular medicine.
I recently read How To Take Smart Notes and have been giving that approach a whirl. I'll re-evaluate after a month or so. The approach is pretty simple and didn't require an entire book to explain.
* Take notes throughout the day. I do this in a notebook.
* At the end of the day, collate those notes into long term storage with a link to the source material.
* When an idea or theme begins to arise, create a document to begin building on that idea, linking to the notes you've taken.
There's a little more regarding organization of notes and linking and so forth. I like the idea and in the short time that I've been practicing this approach I feel like I am getting a much deeper understanding of the texts that I read. Again, time will tell.
I have been journaling since 13 years old. I starting my keeping a blog as a more permanent record when I was 17 years old. I then started systematically saving content to my computer that I’d come across, and finally moved it to the cloud. Most recently I’ve used the app/extension Pocket to archive and save content such as articles.
The best personal knowledge base is my blog.
The act of writing, of pasting work and thoughts and reflections and associations and tagging and organizing, allow me to really embed it in my own memory.
I really gotta process and write it in order for me to really get the most out of the knowledge base I’m saving.
I keep a personal knowledge base with notes on people (SOs, colleges they're from, etc.), a todo list with notes for improvements to my process and workflows, passwords and logins, one liners and snippets (though the only one I use frequently these days are SQL snippets), notes on specific projects, ideas for blog posts in progress, various writing drafts, and old bios, CVs, and copy for personal promotion. It's al orgmode, so not much of a distinction between planning and creating, which I enjoy. You can as easily do literate coding in orgmode as write a blog post or keep notes.
Most of the suggestions here involve organized, and perhaps structured, note taking. This is good and makes sense for personal knowledge/research.
That said when I saw ‘personal knowledge base’ my first thought was ‘personal knowledge graph.’ An advantage of knowledge graphs is the ability to start with public data sources and combine in your own information. Like, customizing DBPedia with your own scheme and data.
For organizations, ontology development, defined vocabularies, etc. make sense, but not for most individuals.
To quote https://www.jvt.me/posts/2017/06/25/blogumentation/ I use blog posts as a way to write easily consumable howtos which I can refer back to when I have issues. I've also found it hugely popular with people finding my site via search engines as well as colleagues facing similar issues
I feel you don't have to be a developer or create your own. But you may have to try out some alternatives before deciding on one - some people prefer browser applications, some people prefer desktop applications, I preferred the former in the past but now prefer the latter...
For many years, I maintained my technical KB as a local WordPress blog (installed using XAMPP. XAMPP is a portable WordPress + MySQL easy to use installer). The main reason was that WP had plugins for code syntax highlighting, searching and organizing content in a hierarchy. But drafting and formatting articles with code and math was (still is, IMO) kind of a pain in WP's editor, which is why I stopped using WP.
I had also tried out some of the wiki software, including PmWiki and MediaWiki. There's nothing bad I can point to, but somehow I just didn't like using them.
Later I switched to plain old Libreoffice Writer. Drafting, formatting and organizing content are a breeze. It doesn't have code highlighting, but I use an online formatter (hilite.me) and just paste the snippets as HTML. Works great for me, exports to PDFs if I want that content in my tablets. Since searching for documents is inconvenient, I keep all the information cleanly organized in directories.
If you like markdown, I suggest RStudio. It's actually an IDE for the R language, but its usability, markdown and export to HTML support are so good that I use it a bit like a WYSIWYG HTML editor when writing content related to data analysis and visualizations. However, it's a desktop application, and some people don't like those.
If you like markdown and prefer web applications, try out any of the static site generators, like Pelican. These usually require a little knowledge of the programming language they're written in and some command line usage.
Key takeaways:
- Make sure the underlying storage is as simple as possible. Markdown in text files is as safe as it gets
- Friction has to be close to zero, otherwise you won't use it
- Put information in a deterministic location. Store any information that you might come back to, so that you don't have to repeat your research.
I'm a big fan of using vim and asciidoctor and an organized notes directory. I quickly jot down notes about certain projects or ideas using vim, then go back and format the notes at a later date with asciidoc markup. Then I run it through the asciidoctor chain to create personal html pages. https://asciidoctor.org/
* A personal Wiki.
* Evernote is a good choice and works across several devices.
* Figure out a folder structure you like and just keep assorted .txt or .md files.
* Google Sheets.
* A commonplace book.
Markdown files in a category of directories. Plain. Easy. Simple. I personally use sublimetext with Markdown Editing, MarkdownExtended (the syntax highlighting is better than markdown editing), Markdown Preview, MarkdownTOC, SearchInProject (uses ripgrep to search contents) and ImagePaste[0]. I sync my knowledge-base with box, but anything would work, including git if you want to commit/pull constantly. I use Mark Text sometimes for output/live editing. I find that the simple syntax highlighting is quite beneficial to organisation and far simpler to use and navigate than ORG mode (plus I wouldn't/didn't really use the org mode advanced features). I also use some firefox plugins to make copying the current title/url as a markdown link easy ('Copy as Markdown...') and a 'paste to markdown' (https://euangoddard.github.io/clipboard2markdown/) web tool—but I'd like to turn the latter into a FF plugin. I write all my documents with these tools initially as well, either transforming to word with pandoc, into html/pdf with MarkdownPreview+PrintPDF (I prefer the formatting to pandoc) or with 'BackSlide' to convert markdown to lecture slides.
The trick is organisation. This is the hard part, but it's also the hard part if you keep paper notes. I have some catch alls, '_inbox.md', '_work.md', '_til.md' (where I keep track of things I've learned today, I try my best to go back and re-read the previous weeks every once in a while) to keep track of random/non-catagorisable notes; but other things exist in 'administation/' (ie. 'administration/linux', 'administration/windows'), 'intersting-articles/', 'programming/*', 'work/meetings/<project>_<date>_<topic>.md'.
If you use sublimetext and the above plugins, cmd/ctrl-r (navigate open doc by symbols) lets you move/search through headings quite easily. My '_work.md' file has a list of dates at the top for when things are due and uses '- [ ]' as checkboxes (which MarkdownPreview outputs as html checkboxes).
I find that as long as I write it down and watch what I'm writing (don't just copy without following your output) it helps to make it stick—or at least gives me a spatial memory of where it might be.
Flexibility is key. But what works for me, probably doesn't work for you. The important part is just to start doing it, write down all the things. Once you find something you'd like to be better about it, improve it. The nice thing about text files is that they are easy to parse and transform into something else.
[0]: To keep allow you to paste images into your markdown files. I've modified it so that it stores the files in a '.images' directory in the same location as the .md file. ImagePaste also has an image preview mode that lets you expand images directly inline in sublime-text.
I write my notes in a plain text file using Vim and just push them to my github repo for backup. I like this method because I can grep for keywords and find information quickly. The point of this personal knowledge is to record important information from books I've read, but so that I don't have to read through the whole book again to find information.
I find it valuable to stay in control of the information that shapes me. Personal curation and modification of the used technology is part of this. Furthermore a personal archive can remain private or even give control over how private certain information remains.
Inside is mostly documentation, to-dos, recommendations of friends, notes, poems etc...
I put project related information in Google Drive, organized in per project folders. I do this for both my personal and company projects; personal ones using my Google account, and company's using its G Suite account.
I like knowledge and learning, so I just used to bookmark articles that were interesting with the intention to read them in the future.
I found that I have too much to read and not enough time.
now I am working on a chrome extension bookmark that save a summarization of the article to a google drive and remind me to read it.
Writing is one of the best ways to learn. A knowledge base provides me with the material that I can use to produce my own thoughts. Unless you write fiction or you have already acquired some kind of deep knowledge about a subject, the process of research and collecting is essential for good writing.
When I started in my current job, I was effectively the single administrator (servers, network(s), clients) at a small-ish company (~70 employees using PCs), and there was a landscape that already was the result of 10+ years of growth without any central planning.
TL;DR - I was thrown into a relatively complex environment with little help other than asking the two guys who had done this before me, both of which were rather busy (they had done the administration a side-business of sorts). (I still wonder how they managed to keep the IT infrastructure running, but in my first few months, many of our users told me how happy they were that I responded to their calls for help right away rather than "sometime next week".)
I used emacs' org-mode. I kept a file where I wrote down every little bit of information I could gather. After 12, maybe 15, months, I had memorized everything I needed to know and stopped taking notes. So my example might not fit your question all that well. But for the time I was getting to know this company's infrastructure, its servers, networks, and people, that .org file was a lifesaver.
I keep notes of tasks, problems, solutions, caveats, and references. This makes for a highly searchable and understandable knowledge base. Anything beyond that proves to have little utility in the long-term.
Quite simply so I can remember the stuff I need to. Or to be more clear, I know I'm going to forget so want to be able to find out what I've forgotten in a convenient way.
I'm really not a fan of these studies, even this article points out why: copying verbatim doesn't work.
Hand writing forces you to rephrase in your own words because you can't write fast enough to keep up—but there's no reason you can't apply this same method to typing, AND get all the benefits of legible, searchable, organisable, easily expandable text documents.
Although high general intelligence is common among hackers, it is not the sine qua non one might expect. Another trait is probably even more important: the ability to mentally absorb, retain, and reference large amounts of ‘meaningless’ detail, trusting to later experience to give it context and meaning. A person of merely average analytical intelligence who has this trait can become an effective hacker, but a creative genius who lacks it will swiftly find himself outdistanced by people who routinely upload the contents of thick reference manuals into their brains.
I'm a researcher. Absorbing data in a "blue sky" kind of way ("no idea if i'll need this, this doesn't serve any explicit purpose, but hey it seems interesting") is a survival trait.